This application claims priority to Japanese patent application number 2001-092711 filed Mar. 28, 2001.
1. Field of the Invention
This invention relates to a temporary retaining structure for a light projecting device or a light receiving device of an automatic focusing apparatus (hereinbelow referred to simply as the AF apparatus) of a camera. The term xe2x80x9clight projecting device or a light receiving devicexe2x80x9d as used herein means at least either one of a light projecting device, such as an infrared light emitting diode (IRED), and a light receiving device, such as a photo position sensor device (PSD), in an active type of AF system.
2. Description of the Related Art
Small-sized cameras ordinarily referred to as compact cameras are provided with a lens barrel unit, which supports a photographing optical system. The lens barrel unit is located approximately at a center region of a front surface side of a camera main body. Also, an instrument supporting frame, which supports a photographing condition setting optical system containing an AF apparatus, a finder apparatus, and the like, is secured at a position above the lens barrel unit. In cases where the AF apparatus is of the active type, the AF apparatus is provided with an AF light projecting section and an AF light receiving section. The light projecting device, such as the IRED, is located at the AF light projecting section, and the light receiving device, such as the PSD, is located at the AF light receiving section.
If the position of the light projecting device or the light receiving device of the AF apparatus, in particular the position of the light receiving device, shifts slightly from a predetermined position, the AF functions will be affected adversely. Therefore, a high position accuracy is required of the light projecting device or the light receiving device of the AF apparatus, in particular the light receiving device. Accordingly, the cameras have heretofore been provided with a position adjusting mechanism, which is utilized for adjusting the position of the light projecting device or the light receiving device of the AF apparatus after the light projecting device or the light receiving device has been combined with the instrument supporting frame. However, due to a limitation imposed upon the cost of the camera, it is not appropriate for a low-cost camera to be provided with the position adjusting mechanism. Accordingly, a technique has heretofore been employed, wherein the accuracy, with which the light projecting device or the light receiving device is combined with the instrument supporting frame, is enhanced such that the adjustment of the position of the light projecting device or the light receiving device need not be performed, and wherein, after the light projecting device or the light receiving device has been combined with the instrument supporting frame at the predetermined position of the instrument supporting frame, the device is adhered to the instrument supporting frame by use of an adhesive agent.
However, in cases where the light projecting device or the light receiving device is secured to the predetermined position on the instrument supporting frame by use of the adhesive agent, the problems occur in that the light projecting device or the light receiving device shifts from the predetermined position due to shrinkage of the adhesive agent at the time of the hardening of the adhesive agent. Therefore, in order to eliminate the problems described above, a technique has heretofore been employed wherein, after the light projecting device or the light receiving device has been incorporated to the predetermined position on the instrument supporting frame from a back side of the instrument supporting frame, the device is held from the back side by use of a retaining member until the adhesive agent hardens, and the device is thereby prevented from shifting from the predetermined position.
However, in cases where, for example, the AF apparatus and the finder apparatus are formed together as an integral body, and a prism and an eye-piece of the finder are located on the side backward from the section for mounting the light projecting device or the light receiving device of the AF apparatus, since it becomes impossible to draw a mold toward the side backward from the instrument supporting frame at the time of a process for molding the instrument supporting frame, the temporary retaining structure in which the light projecting device or the light receiving device is held from the back side by use of the leaf spring, or the like, cannot be employed.
Also, from the view point of cost, it is not advantageous that the particular independent retaining member, such as the leaf spring, is required.
The primary object of the present invention is to provide a temporary retaining structure for a light projecting device or a light receiving device of an AF apparatus, wherein a particular independent retaining member, such as a leaf spring, need not be utilized, and the light projecting device or the light receiving device is capable of being prevented from shifting from a predetermined position during an adhering process even in the cases of a constitution, in which a prism and an eye-piece of a finder are located on the side backward from a section for mounting the light projecting device or the light receiving device.
The present invention provides a temporary retaining structure for a light projecting device or a light receiving device of an automatic focusing apparatus for use in a camera provided with an instrument supporting frame, with which a light projecting device or a light receiving device of an automatic focusing apparatus are combined at a predetermined position,
wherein a retaining piece, which is capable of elastically pushing and holding the light projecting device or the light receiving device at the predetermined position, is formed through integral molding together with the instrument supporting frame.
In the temporary retaining structure for a light projecting device or a light receiving device of an automatic focusing apparatus in accordance with the present invention, the light projecting device or the light receiving device is held by the retaining piece at the predetermined position, and the light projecting device or the light receiving device is adhered in this state to the instrument supporting frame by use of an adhesive agent.
With the temporary retaining structure for a light projecting device or a light receiving device of an AF apparatus in accordance with the present invention, the retaining piece capable of elastically pushing and holding the light projecting device or the light receiving device, which is combined with the instrument supporting frame, at the predetermined position, is formed through the integral molding together with the instrument supporting frame. Therefore, a particular independent retaining member, such as a leaf spring, need not be utilized, and the light projecting device or the light receiving device is capable of being prevented from shifting from the predetermined position due to shrinkage of the adhesive agent at the time of the hardening of the adhesive agent.
Also, with the temporary retaining structure for a light projecting device or a light receiving device of an AF apparatus in accordance with the present invention, even in cases where a prism and an eye-piece of a finder are located on the side backward from the section for mounting the light projecting device or the light receiving device, the structure of the instrument supporting frame may be set such that the light projecting device or the light receiving device is combined with the instrument supporting frame from above the instrument supporting frame, and the retaining piece is thereby capable of being formed through the integral molding together with the instrument supporting frame.